Brake mechanism for saw



(N0 Model.)

B. FISCHER.

I BRAKE MBGHANISM FOR SAWING MACHINES. No. 371,533.

Patented Oct. 11, 1887.

v \I. Maw! v 3 .7|/ I IN VEJV T 0R M r M 7 3% WIZWESSES .L/ TTORJVE YENGELBERT FISCHER, OF CHICAGO, ILLINOIS.

BRAKE lVlECHANlSM FOR SAWING=MACH|NES.

SPECIFICATION forming part of Letters PatentNo. 371,533, dated October11, 1887.

Application filed March 31, 1887. Serial No. 233,237. (No model.) 7

To all whom it may concern.-

Beit known that I, ENGELBERT FISCHER, a citizen of the United States,and a resident of Chicago, county of Cook, and State of Illinois, haveinvented new and useful Improvements in Brake Mechanism forSawing-Machines, of which the following is a specification, referencebeing had'to the accompanying drawings, illustrating the invention, inwhich- Figure I is a perspective representation of a mechanism embodyingmy invention; Fig. II, a perspective and enlarged view of a de tachedpart thereof.

This invention relates to the applying of a brake to that class ofcircular sawing machines which are employed for crosscutting lumber,planks, or boards in short lengths by a rotary saw which is fed to thelumber automatically by means of a reciprocating carriage. The purposeof the brake is to prevent the band which moves the carriage forwardfrom getting out of taut duringthe backward movement of the carriage.Unless this be done the saw will not at all times bebrought to the samestopping-point, and as a result the plank will not be cut off. My meansto attain this end by a brake is as follows:

A represents the main frame of the ma chine, which is of the ordinaryconstruction, except where bearings are provided for the mechanismherein described and shown.

Bis the bed of the saw-carriage O, and to this carriage is hung thesaw-arbor D,to which the saw F is hung.

J is a shaft journaled in frame A and supporting a drive-pulley, K, andfriction-pulley L.

M is a compensating tightener-frame hung to shaft J and carrying loosepuileysN N. A belt from the arbor D is to run over pulleys N N'K andgive proper motion to frictionpnlley L, in accordance with the motion ofthe saw; but the devices to attain this end are not to be considered apart of this invention, they being shown only to illustrate how myimproved brake operates. The opposite end of the shaft J is journaled inbox 5, which may have a vertical reciprocating movement in guides T onframe A, as more clearly shown at Fig. II, to engage and disengage thewheels L Q.

A coil-spring, U, placed above the journalbox S, keeps the wheel L fromwheel Q till the box is operated on by the following means: An elbowlever, \V U, is journaled in the lower part of the frame A at V, and itsinner end projects under the box S, so that when the outer bar, V, ofthe lever is brought down the box S will be so elevated as to bring thewheel L in contact with wheel Q. To hold the said wheels in contactwhile the carriage O is moving forward, a trip-lever, a, is pivoted tothe frame A at b, and its lower end is provided with a notch, c, whichengages and locks the lever -W till the carriage G, or a projecting bar,m on the carriage, strikes the top of lever a and moves it back,carrying the lower end, 0, in and releasing lever \V. To keep the leverWV locked by lever a till acted on by the bar m, a spring, 19, isattached to the front of the machine to bear against it above the jointI), as shown at Fig. I. The positions of the parts in said figure showthe lever W locked by lever on to hold the wheel L to rotate by frictionthe wheel Q. A shaft, P, supports the wheel Q, and also a smaller wheel,e, and the small wheel and loose wheel 4 carry the strap 2 (dottedlines) for drawing the carriage 0 forward to bring the saw F to thelumber. The other part of this machine, having a well-knownconstruction, will causethe carriage O to move quickly back so soon asthe lever to is tripped. Now, to prevent the wheel 0 from letting thebelt 2 run slack, I applya brake to the wheel Q, of the followingconstruction: A bar, 9, is jointed to the front end of the machine ator, and it is provided with a shoe, j, which at all times exerts justforce enough to stop the wheel Q in less time than is required to unwindthe strap 2. This resisting force is so little that no inconvenience isencountered thereby in running the machine, yet enough force to hold thestrap .2 taut must be applied, or the carriage G will have differentstopping-points. Connected with the top end of the brake g is a bar orrod, h, which extends through the opposite end of the machine-frame, andon its end is rod attachments h i n, the levers W,U, and a, applied acoil-spring, 'i,whioh may have given and the sliding box S, fordisengaging the to it more or less tension by a jam-nut, n, that wheel Lfrom wheel Q, so that the brake gf the brake gf may have more or lesspressure will retard the motion of the strap-whee1 e, 5 on wheel Q. andthus keep the strap 2 taut, as specified I 5 From the foregoing itewillbe seen that the and shown. 1 wheel 6 is only stopped when the wheel Lis ENGELBERT FISCHER. disengaged with wheel Q. \Vitnesses: Y R

I claim as my invention- I G. L. GHAPIN 1 o In combination with thebrake g f and its GHAs. SIMoNsoN.

